Ranking the 5 AL West aces entering the 2023 season

4) RHP Luis Castillo - Seattle Mariners

The Mariners traded a ton to acquire Luis Castillo at the trade deadline from the Reds and for good reason. He's a legitimate ace who transformed their rotation from good to great. Castillo leads a staff joined by the likes of Robbie Ray, Logan Gilbert, and George Kirby. Despite the good pitchers in the staff, Castillo is the best one.

Overall in 2022, Castillo went 8-6 with a 2.99 ERA in 25 starts. He threw 150.1 innings despite missing the first month of the season with injury. In those innings, he struck out 167 batters (10.0 K/9) and walked 45 (2.7 BB/9). He's a guy who can reach triple digits with his fastball and has one of the nastiest changeups in the game.

Castillo showed how good he was in the postseason when he threw 7.1 scoreless innings in the Mariners' first postseason game in over 20 years leading them to a win in Toronto. He then threw another 7 innings allowing just three runs to the eventual champion Astros. He is a force the Angels will have to deal with which is not fun.

3) LHP Framber Valdez - Houston Astros

The Astros do not have the best of everything in the division, as with Justin Verlander departing, Houston lost the best pitcher in the AL West. Verlander is coming off arguably his best season in the bigs and another Cy Young Award. Thankfully he is on the other side of the country and in the other league pitching for the New York Mets in 2023.

Now onto Framber Valdez, the heir apparent to Verlander. Valdez is an elite pitcher who had at one point this past season a string of 25 consecutive quality starts which broke a single-season record. He was one quality start shy of tying the overall record of 26 consecutive quality starts set by Jacob deGrom and Bob Gibson.

Valdez allowed two runs or fewer in all four of his postseason starts including seven scoreless innings against the Yankees in the ALCS. Houston lost an ace but had one waiting in the wings the entire time.